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Öğe Conductivity and band gap of oligo-2-[(4-fluorophenyl) imino methylene] phenol and some of its oligomer-metal complexes(Pergamon-Elsevier Science Ltd, 2006) Kaya, İsmet; Koyuncu, Sermet; Senol, DilekSchiff base oligomer of 2-[(4-fluorophenyl) imino methylene] phenol (FPIMP) was synthesized via oxidative polycondensation reaction in an alkaline medium. Oligomer-metal complex compounds were synthesized from the reactions of oligo-2-[(4-fluorophenyl) imino methylene] phenol (OFPIMP) with Co+2, Ni+2 and CU+2 ions. The synthesis was achieved by oxidative coupling based on air oxygen as an oxidant. While synthesized Schiff base oligomer was soluble in most common organic solvents, its metal complexes were only soluble in dimethylsulfoxide. Electrochemical HOMO and LUMO band gap (E-g) of monomer, oligomer and its metal complexes were calculated from oxidation and reduction onset values. According to cyclic voltammetry (CV) and UV-vis measurements, electrochemical energy gaps (E-g(l)) and optical band gap 9 (E-g) values of monomer and oligomer were found to be 3.26 and 3.10; 3.15 and 2.96 eV, respectively. Conductivity measurements of doped and undoped Schiff base oligomer and its metal complexes were carried out by electrometer at a room temperature and atmospheric pressure and were calculated from four-point probe technique. When iodine was used as doping agent, conductivity of this oligomer and its metal complexes were observed to be increased. (c) 2006 Elsevier Ltd. All rights reserved.Öğe Phenol side-groups-containing fluorene polymer synthesized by catalytic oxidative polymerization(Wiley, 2011) Bilici, Ali; Kaya, İsmet; Senol, DilekCatalytic oxidative polymerization (OP) of 4,4'-(fluorene-9,9-di-yl) diphenol (FDP), possessing both phenol and fluorene rings in its structure, was carried out in different organic solvents. Schiff base polymer-copper (II) complex and hydrogen peroxide were used as a catalyst and an oxidizing agent, respectively. The structure of poly (4,4'-(fluorene-9,9-di-yl) diphenol) (PFDP) was confirmed by UV-vis, FT-IR, NMR spectroscopies. Further characterization was conducted by means of thermogravimetric analysis (TGA), DSC, XRD, scanning electron microscopy (SEM), cyclic voltammetry (CV), and conductivity measurements. PFDP showed the optical band gap of 3.09 eV, the emission maximum at 335 nm, and the HOMO level of -5.75 eV. Copyright (C) 2010 John Wiley & Sons, Ltd.Öğe Syntheses of poly(phenoxy-imine)s anchored with carboxyl group: Characterization and photovoltaic studies(Elsevier, 2018) Kaya, İsmet; Ayten, Bahar; Senol, DilekA serious of pyridine based Schiff bases (M1, M2, and M3) were synthesized via condensation reaction of 4-aminosalicyclic acid with 2-pyridinecarboxaldehyde, 3-pyridine carboxyaldehyde and 4-pyridinecarboxaldehyde, respectively. The transformation of Schiff bases into their poly(phenoxyimine) species (P1, P2, P3) was obtained using oxidative polycondensation (OP) by NaOCl as the oxidant in alkaline medium at 70 degrees C. The structures of the synthesized compounds were characterized by solubility test, FT-IR, UV-Vis and NMR techniques. Thermal data were obtained by TG-DTA and DSC techniques. Photoluminescence (PL) properties of the synthesized materials were examined in organic solvent. Fluorescence measurements were carried out in various concentrated solutions to determine the optimum concentrations and PL intensities. P3 could be used in light-emitting diodes due to its multi-color (white, blue, green and yellow) light-emitting property. The efficiency (eta) of a solar cell of P1, P2 and P3 were determined by single channel Potentiostat/Galvanostat with electrochemical impedance spectroscopy. The order of conductivities was found to be as P3>P2>P1 as a result of iodine doping. The best performing photovoltaic cell with I-sc (mA cm(-2)), V-oc (V), FF, and eta (%) as -0.642, 0.399, 0.461 and 0.118 was obtained for P3. (C) 2018 Elsevier B.V. All rights reserved.Öğe Synthesis and characterization of aromatic compounds containing imine and amine groups via oxidative polycondensation(Taylor & Francis Ltd, 2014) Senol, Dilek; Kaya, İsmetIn this study, Schiff bases compounds were synthesized from the condensation of 3,5-diaminobenzoic acid and 4,4-diaminobenzanilit with salicylaldehyde, o-vanillin, 4-hydroxy benzaldehyde, and 2-hydroxy-l-naphthaldehyde. The derived monomers were changed into their polyphenol species by oxidative polycondensation in aqueous alkaline medium by using NaOCl as the oxidant. At the optimum reaction conditions, the yield of 3,5-bis((2-hydroxynaphthalen-1-yl)metyleneamino) benzoic acid was 69%. The structures of the monomers and polymers were confirmed by FTIR, ultraviolet-visible (UV-vis), H-1-NMR, and C-13-NMR analyses. The H-1-NMR and C-13-NMR data showed that polymerization preceded by C-C and C-O couplings of the monomer units (phenylene and oxyphenylene groups). The molecular weight distribution of the product was determined by size exclusion chromatography. The number-average molecular weight (M-n), weight-average molecular weight (M-w), and polydispersity index of P-4,4-DABAVA were 20,970, 15,420gmol(-1), and 1.36 for NaOCl oxidant, respectively. The CV behaviors electrochemical HOMO, LUMO, and energy gaps (E-g) were investigated using glassy carbon electrode as the working electrode. Optical E-g band gaps were made UV-vis measurements. Solid-state electrical conductivities of both doped and undoped states of the synthesized polyphenols were evaluated showing that conductivity of P-3,5-DABAHNA is better than other polymers. Optical properties were investigated by UV-vis and fluorescence analyses. Maximum fluorescence intensity was obtained from the solution of P-3,5-DABAVA.Öğe Synthesis and characterization of azomethine polymers containing ether and ester groups(Elsevier Science Bv, 2017) Senol, Dilek; Kaya, İsmetIn this study, Schiff base was synthesized from the reaction of 4-carboxybenzaldehyde and 4-amino-3-methyl. Then, the obtained Schiff base was acted with aromatic and aliphatic dihalogen compounds in argon environment, and the polymers containing both ester and ether groups were obtained. For the structural analyses of synthesized substances FT-IR and NMR analysis, for the optical properties fluorescence and UV-Vis measurements, and for the thermal analyses TG-DTA and DSC techniques were used. In addition, electrochemical and electrical conductivity measurements were carried out. Aromatic imine polymers and their derivatives were already synthesized, and the properties such as high thermal resistance, low band gap and semi-conductive properties were also described in literature. In this study, new kinds of polymers synthesized are expected to have a high thermal resistance with elastic aliphatic and conjugated aromatic groups. The effects of the presence of etheric bonds and ester groups in the main chain of the polymers on several physical and thermal properties are also aimed to be explored. (C) 2015 The Authors. Production and hosting by Elsevier B.V. on behalf of King Saud University.Öğe Synthesis and characterization of epoxy resins containing imine group and their curing processes with aromatic diamine(Taylor & Francis Inc, 2019) Kaya, İsmet; Gul, Murat; Senol, DilekThe epoxy resins containing imine bonding were prepared from hydroxyl substituted Schiff base monomers in two steps. At the first step, hydroxyl substituted Schiff base monomers were synthesized via condensation reaction. At the second step, epoxy resins were synthesized from the reaction between Schiff base monomers and epichlorohydrine (EPC). Then curing processes of epoxy resins were achieved by p-phenylenediamine compound. The structures of resulting compounds were confirmed by FT-IR, UV-Vis and H-1-NMR. TG-DTA and DSC measurements were performed for thermal characterizations of the compounds. Chemical resistances of the cured epoxy-amine systems were determined for coating applications in acidic, alkaline and organic solvents. HCl (10%, aqueous solution), NaOH (10%, aqueous solution), DMSO, DMF, N-methylpyrrolidone, ethanol, THF and acetone were used for corrosion tests. Chemical resistance data of the synthesized epoxy resins demonstrated that they have good chemical resistance against various acid, alkaline and common organic solvents. Surface morphologies of epoxy resin and the cured epoxy resin were determined with scanning electron microscopy (SEM) measurements. Also, optical band gap (E-g) values of Schiff base monomers and epoxy resins were calculated from UV-Vis measurements.Öğe Synthesis and characterization of fluorescent graft fluorene-co-polyphenol derivatives: The effect of substituent on solubility, thermal stability, conductivity, optical and electrochemical properties(Elsevier, 2010) Kaya, İsmet; Yıldırım, Mehmet; Aydın, Aysel; Senol, DilekA series of fluorene Schiff bases and their oligophenol derivatives were successfully synthesized using the condensation and graft copolymerization reactions, respectively. The synthesized compounds were good soluble in common organic solvents. Photoluminescence (PL) properties of the synthesized materials were determined in solution forms. As to the fluorene copolymers (FPs), higher PL intensities were obtained when compared with the monomeric models. Solvent effects on the fluorescence spectra and possible usages in spectrofluorometric ion sensors of the FPs were discussed. Optical and electrochemical band gaps of the polymers were lower than those of the Schiff bases indicating the more conjugated structures of the FPs. The oxidized states of the novel fluorene compounds were also examined by cyclic voltammetry (CV) technique. The solid state conductivity measurements showed that the synthesized FPs were semiconductors and when exposed to the iodine vapour their conductivities could be increased up to four orders of magnitude. The polymer having the lower band gap (FP-3) had also the highest undoped conductivity. Thermal characterizations of the synthesized compounds were carried out by TG-DTA and DSC methods. The initial degradation temperatures of the FPs were found quite high in the range of 220-300 degrees C. (C) 2010 Elsevier Ltd. All rights reserved.Öğe Synthesis and Characterization of Novel Polyamines Containing Different Substitute Groups Via Chemical Oxidative Polymerization(Wiley-V C H Verlag Gmbh, 2015) Senol, Dilek; Kaya, İsmetIn this study, polymers of substitute aromatic amine compounds were synthesized by chemical oxidative polycondensation in aqueous alkaline medium using NaOCl as oxidant. The structures of synthesized compounds were confirmed by FT-IR, UV-Vis and NMR analyses. The characterizations of synthesized compounds were made by fluorescence, TG-DTA, DSC, scanning electron microscopy (SEM) and Brunauer-Emmett-Teller (BET) surface area measurements. In addition, electrochemical and electrical conductivity values of compounds were carried out with cyclic voltammetry (CV) and four points probe technique measurements, respectively. Synthesized polymers viewed structural change, optical, electrochemical and thermal differences.Öğe Synthesis and characterization of substituted poly(naphthalene)s with imine bonding containing thiophene unit(Elsevier Science Sa, 2019) Senol, Dilek; Kaya, İsmetIn this study, 5-(4H-dithieno[3,2-b:2',3'-d]pyrrol-4-yl)naphthalen-1-amine was synthesized from the required reaction conditions of 3,3'-dibromo-2,2'-bithiophene with 1,5-diamine naphthalene. Then, Schiff base monomers were synthesized from the condensation reactions of 5-(4H-dithieno [3,2-b:2',3'-d]pyrrol-4-yl)naphthalen-1-amine with mono aldehydes such as 2-hydroxybenzaldehyde, 4-hydroxybenzaldehyde and isovaniline. The Schiff base monomers were polymerized via oxidative polycondensation in 0.1 M KOH aqueous solution at 90 degrees C by 10-15% NaOCl oxidant. The structures of synthesized compounds were carried out by FT-IR, UV-Vis, H-1 NMR, C-13 NMR techniques. Further characterization was implemented by cyclic voltammetry (CV) electrochemical properties, fluorescence (FL) measurements, electrical properties, thermogravimetric-differential thermal analysis (TG-DTA) and differential scanning calorimetry (DSC) measurements. Depending on structural changes of synthesized polymers, differences were observed for the optical, electrochemical, thermal and physical properties. The optical and electrochemical band gaps, conductivity and fluorescence properties of P1 were found to be better than other polymers. The fluorescence intensity of P1 in two different wavelengths was found to be 632 a. u. and 1000 a.u. The optical (E-g) and electrochemical band gap values (E'(g)) of P1 were found to be 2.34 and 2.25 eV, respectively. This low band gap values have demonstrated to be a good conjugation in the structure. According to TG measurements, T-on temperature of P1, P2 and P3 were found to be 227, 293 and 306 degrees C, respectively. The weight average molecular weight (Mw) of P1, P2 and P3 were calculated to be 39500, 40150 and 44300 Da, respectively.Öğe Synthesis and Characterizations of Poly(phenoxy-Imine)s via Catalyzed Oxidative Polymerization by Polymer-Metal Complex(Springer Heidelberg, 2017) Senol, Dilek; Kaya, İsmetIn this study, Schiff base was synthesized from the condensation reaction of 3,5-diaminobenzoic acid, 4,4-diaminobenzanilide, vanillin with 4-hydroxybenzaldehyde. Then, Schiff bases polymers were synthesized via oxidative polycondensation method in the presence of catalyst (polymer-metal complex) in organic solvent. Schiff base polymers were compared to the ones which were previously polymerized without catalyst. The structures of synthesized monomers and polymers were determined by FT-IR, NMR, SEC and SEM analyses; the optical characteristics by UV-Vis and fluorescence spectroscopy methods, solid state conductivity measurements by four-point probe technique, the electrochemical properties by CV analysis, thermal behaviors by TG-DTA and DSC measurements were effectively determined. Depending on the synthetic method of polymer, structural change, optical, electrochemical and thermal differences were measured. Availability of these polymers in the production of light-emitting diode, electronic-optoelectronic and thermal resistant materials was explored.Öğe Synthesis, Characterization, Electrical Conductivity and Fluorescence Properties of Polyimine Bearing Phenylacetylene Units(Springer/Plenum Publishers, 2016) Senol, Dilek; Kolcu, Feyza; Kaya, İsmetIn this study, a Schiff base was synthesized by the condensation reaction of 4-bromobenzaldehyde and 4-aminophenol. Then, phenylacetylene substituted Schiff base monomer (IPA) was obtained by HBr elimination reaction of IPA with phenylacetylene through Sonogashira reaction. IPA was polymerized via chemical oxidative polycondensation reaction. FT-IR and NMR measurements were used for the structural analyses of the synthesized substances. Fluorescence and UV-Vis analyses were carried out for optical characterization. Electrochemical characteristics, electrical conductivities and thermal properties were determined using cyclic voltammetry (CV), four-point probe conductometer, TG-DTA and DSC methods. The main purpose of the present study was to investigate the effects of phenylacetylene bearing units on the properties of conjugated aromatic polyimines. The spectral analysis signified a green light emission behavior when irradiated at different wavelengths. Combined with fluorescent behavior and good thermal stability, the electrical conductivity was found to be very crucial for pi-conjugated polymer.Öğe Synthesis, characterization, optimum reaction conditions, and some polymer-metal complexes of poly(phenoxy-imine)s containing furan ring(Springer, 2018) Kaya, İsmet; Orta, Ibrahim Erdem; Ozdemir, Eyup; Senol, DilekIn this study, Schiff bases containing azomethine (-HC=N-) compounds were synthesized from the condensation reaction of 4-aminophenol and 2-aminophenol and 5-methyl-2-furaldehyde. Orange-colored Schiff bases, 4-[(5-methyl- 2-furyl) methyleneamino] phenol (4MFMAP) and 2-[(5-methyl-2-furyl) methyleneamino] phenol (2MFMAP) turned to poly-4-[(5-methyl-2-furyl) methyleneamino] phenol (P-4MFMAP) and poly-2-[(5-methyl-2-furyl) methyleneamino] phenol (P-2MFMAP) polyazomethine derivatives by NaOCl oxidant in alkaline aqueous medium. In addition, poly-2-[(5-methyl-2-furyl) methyleneamino] phenol cobalt (II) and copper (II) complexes were synthesized. FTIR and NMR measurements for structural analysis of the synthesized compounds, UV-Vis analysis for optical properties, electrical conductivity measurements, and thermal analysis with the TG-DTA techniques were determined. The yield of P-4MFMAP and P-2MFMAP was found to be 84.6% and 78.6 as follows [4MFMAP] = 0.066, [KOH] = 0.198 [NaOCl] = 0.066 mol L-1 at 60 A degrees C for 3 h and [2MFMAP] = 0.066, [KOH] = 0.132 [NaOCl] = 0.066 mol L-1 at 70 A degrees C for 3 h, respectively.Öğe Synthesis, Structural Characterization, Enzymatic and Oxidative Polymerization of 2,6-Diaminopyridine(Springer/Plenum Publishers, 2020) Senol, DilekEnzymatic polymerization of 2,6-diaminopyridine (DAP) compound in the presence of HRP (Horse radish peroxidase) and H2O2 (hydrogen peroxide) with Poly(DAP-en) with the structures of two different types of polymers obtained by the oxidative polymerization of Poly(DAP-ox) using H2O2 in an aqueous basic environment was illuminated by H-1-NMR, C-13-NMR, FT-IR, UV-Vis spectral methods. GPC (gel permeation chromatography), TGA (thermal gravimetric analysis), DSC (differential scanning calorimetry), CV (cyclic voltammetry), fluorescence analysis and conductivity measurements to characterize the compounds and their electronic structure were examined. SEM analyzes were performed for the morphological properties of the compounds. As a result of the analysis, it was observed that the polymer obtained by enzymatic polymerization was better than the polymer obtained by oxidative method. It was observed that the results of the fluorescence measurements were better than Poly(DAP-en) in Poly(DAP-ox) emitting blue and green light. According to TGA analysis, the first decay temperatures for Poly (DAP-en) and Poly (DAP-ox) were calculated as 342 degrees C and 181 degrees C, respectively. The higher value of glass transition temperature for poly (DAP-en) confirms that the average molar mass is higher than 8650 Da for Poly (DAP-en) according to GPC analysis.
